Friday December 19, 2008

Delta Airlines is going to do a daily 777-200 service LAX-SYD from July 1 (Chicago Trib story here with reactions from the United/Chicago perspective). Qantas will still have the lion’s share of the capacity on the route, but by mid-2009 it looks like there will be four options for LAX to SYD (Qantas, United, V-Australia and Delta). Its a very profitable set of routes for QF and UA at the moment, and its not surprising that others want in.

Random observations:

Its certainly an interesting time for extra inventory to be opening up on USA-Australia routes. Cheaper jet fuel trumps the collapse in the global economy?

Delta is so big (post Northwest merger) that it should have no trouble filling its 772 to SYD.

QF is said to have 70% of the current inventory; the routes are said to the be the source of 20% of QF’s profits. You see an awful lot of QF aircraft at LAX; according to the LA Times, QF can sometimes have four flights a day out of LAX, making it LAXs busiest foreign carrier. I know that UA does a daily 744 out of both LAX and SFO to SYD, and during the Christmas peak this can go up to 2 flights a day, and UAL is back to non-stops LAX-MEL. Air New Zealand can be a viable alternative either for people headed for non-SYD destinations like MEL or BNE.

The argument for keeping Singapore off that route is looking even more silly than before.

The 777 is a slightly nicer aircraft to fly in than United’s 744s, but a little slower. Mind you, I’ve only ever flown UA 777s.

QF appears to be the only carrier to go nonstop to BNE from the West coast of the United States (LAX). V-Australia is talking about BNE-LAX 3 times a week too with 773ERs.

V-Australia will presumably do some nice integration with Virgin Blue; part of QF’s stranglehold is the way it can integrate the international traffic with any domestic travel within Australia. The downside of that is that any thoughts of UA doing any partnering with Virgin Blue is probably now over given that V-Australia is competing with UA on the trans-Pacific route. Likewise, Delta won’t have a Australian domestic partner.

Thursday December 18, 2008

This one got past the spam filter. I wonder how many other stats/polmeth people got this one?

Dear Sir,
you are my last hope. I am from [deleted]. I need to write the full code (in matlab) of a program that generates random numbers from the gamma distribution. Please help me.
Hope to hear from you, [deleted]

Accept-reject seems to be the preferred algorithm, with R using the Ahrens and Dieter algorithms (e.g., Communications of the ACM, 1982 V25(1):47-54). A quick glance suggests it wouldn’t be hard to code from scratch.

See also this video shot by a United pilot (Capt Walter Bates) on his retirement flight (SYD-SFO, my family and I happened to be on board). From Capt Bates:

I also include a video of our landing in SFO from about 1,000′ altitude on down – that’s Coyote Point Yacht Harbor off to the left at the start of the video. Just before touchdown you hear the automated voice of our radar altimeter calling off 50, 30, and 10 feet above the runway – and that’s calibrated from the bottoms of the first main wheels to touch the pavement. At touchdown my eyes are still nearly 60 feet up. At this point our inertial guidance system is being updated by transmitters on the end of the runway giving us an accuracy of less than 2 feet. With this system we can land with visibility of only 600 feet. We touched down at about 170 mph being over 350,000# lighter than at takeoff and use reverse thrust from the engines and a sophisticated antiskid braking system to get it stopped. All takeoffs and over 99% of landings are done manually. Only in Hollywood do autopilots do so much flying.

At the start of the takeoff roll on Sydney’s runway 16R we weighed the aircraft limit of 875,000# (the max for the C5 Galaxy is 769,000#). This included nearly 400,000# of fuel (there are 6.7# per gal.). It took over 60 seconds and 2,000# of fuel to accelerate to a speed of 187 knots – about 215 mph – where the 16 main wheels left the runway. We used 11,500′ of the 13,000′ runway…. The takeoff video is of the first 1:54 minutes of the flight. Have the volume up as full audio is included. At the start of the video you hear Sydney tower’s takeoff clearance to us over the cockpit speaker referring to runway 16R. My “93%” and “1.43 EPR” comments refer to the power setting for takeoff – nearly full power. That is 224,000# of thrust that is held for the first 100 seconds and you hear the engines come up clearly. The “80 knots” call identifies the latest time by which takeoff power must be set. The call of “V1″ (156 knots) occurred at the precalculated last point where we could abort the takeoff and stop on the runway. After that we’re committed to go though certification and weight limits insure that if the most critical engine (they’re not equally important) were to fail at that point we could still climb away safely. The “VR” call (174 knots) is where we lift the nose about 20 degrees. The “V2″ call is when we lift off. You clearly see the marks identifying the approaching opposite end of the runway going by at this point. If the speeds don’t look that fast it is because the camera, and my windshield, are 32 feet above the ground. After liftoff you have a nice view of Botany Bay ahead.